In 2003, Okinawan high schooler Miu gets interested in Minato-senpai, who has just lost his both parents. She cheers him up by exchaning MiniDisk mix tapes with him. They start a long-distance relationship when Minato graduates and moves to Tokyo, and Miu eventually follows him to Tokyo for college. Some years later, while Miu is struggling with her job hunting, Minato suddenly breaks up with her, and she returns to Okinawa. 15 years later in 2024, Miu is married to her childhood friend Ryusei, and is now terminally ill. Her daughter Himari is sent to Tokyo to deliver a message on a MiniDisk to the man her mother loved.